Analysis of norovirus infections among outpatients with suspected viral diarrhea in Shenzhen,from 2019 to 2021
Objective To evaluate norovirus(NoV)infection and genetic characteristics of norovirus among outpatients with suspected viral diarrhea in Shenzhen city from 2019 to 2021,and provide primary data for the prevention and treatment of NoV.Methods A total of 2 494 stool samples from outpatients with suspected viral diarrhea were collected from the Shenzhen viral diarrhea surveillance network from January 2019 to December 2021.All samples were analyzed by RT-PCR to detect NoV,and sequence analysis was conducted for the positive samples."Noroviurs Typing Tool version 2.0"was used for genotyping,and the epidemiological data were statistically analyzed.Results The overall NoV detection rate in Shenzhen from 2019 to 2021 was 19.93％(497/2 494);with 22.50％,17.55％and 18.90％in each year respectively.The detection rate of NoV was 21.12％(297/1 406)in male and 18.38％(200/1 088)in female;there was no significant difference between male and female(x=2.889,P＞0.05).Across all age groups,the highest detection rate was 31.25％(25/80)for the 15-＜20 age group,followed by 23.47％(134/571)for the 1-＜5 age group,23.15％(254/1 097)for the ≥20 age group,19.05％(28/147)for the 5-＜15 age group,14.55％(40/275)for the 6 months-＜1 age group,and 4.94％(16/324)for the 0-＜6 months group.In 2019 there was no obvious peak of NoV infection,but in 2020 and 2021 the peak occurred in autumn and winter.In 2019 and 2021,there were 11 and 10 samples which were infected with mixtures of NoV and other diarrhea viruses respectively.The results of RT-PCR showed that from 2019 to 2021,NoV type GⅡ was the most common type,which accounted for 77.78％,79.31％,81.82％,and there was also a small amount of mixed infection of NoV type GⅠ and GⅡ.Further genotyping results showed that among the 497 samples infected with NoV,we took 420 samples for genotyping,which produced a total of 435 typing items,and GⅡ.4 was the most prevalent NoV strain(48.97％,213/435),followed by GⅡ.2(12.41％,54/435)and GⅡ.17(9.43％,41/435).In addition,15 genotypes,such as GⅠ.5 and GⅡ.3,were detected in 1 out of 25 samples.Conclusions NoV infection in suspected viral diarrhea cases in Shenzhen still maintained a high level,and there were many types of infection in the population.Thus,the risk of cluster outbreaks still remained,and it should be necessary to maintain close surveillance of NoV.
万方数据
维普
